gecko/media/gmp-clearkey/0.1/ClearKeyDecryptionManager.cpp

402 lines
11 KiB
C++

/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include <assert.h>
#include <sstream>
#include <stdint.h>
#include <stdio.h>
#include "ClearKeyDecryptionManager.h"
#include "ClearKeyUtils.h"
#include "mozilla/NullPtr.h"
using namespace mozilla;
using namespace std;
class ClearKeyDecryptor
{
public:
ClearKeyDecryptor(GMPDecryptorCallback* aCallback, const Key& aKey);
~ClearKeyDecryptor();
void InitKey();
void QueueDecrypt(GMPBuffer* aBuffer, GMPEncryptedBufferMetadata* aMetadata);
uint32_t AddRef();
uint32_t Release();
private:
struct DecryptTask : public GMPTask
{
DecryptTask(ClearKeyDecryptor* aTarget, GMPBuffer* aBuffer,
GMPEncryptedBufferMetadata* aMetadata)
: mTarget(aTarget), mBuffer(aBuffer), mMetadata(aMetadata) { }
virtual void Run() MOZ_OVERRIDE
{
mTarget->Decrypt(mBuffer, mMetadata);
}
virtual void Destroy() MOZ_OVERRIDE {
delete this;
}
virtual ~DecryptTask() { }
ClearKeyDecryptor* mTarget;
GMPBuffer* mBuffer;
GMPEncryptedBufferMetadata* mMetadata;
};
struct DestroyTask : public GMPTask
{
explicit DestroyTask(ClearKeyDecryptor* aTarget) : mTarget(aTarget) { }
virtual void Run() MOZ_OVERRIDE {
delete mTarget;
}
virtual void Destroy() MOZ_OVERRIDE {
delete this;
}
virtual ~DestroyTask() { }
ClearKeyDecryptor* mTarget;
};
void Decrypt(GMPBuffer* aBuffer, GMPEncryptedBufferMetadata* aMetadata);
uint32_t mRefCnt;
GMPDecryptorCallback* mCallback;
GMPThread* mThread;
Key mKey;
};
ClearKeyDecryptionManager::ClearKeyDecryptionManager(GMPDecryptorHost* aHost)
: mHost(aHost)
{
CK_LOGD("ClearKeyDecryptionManager ctor");
}
ClearKeyDecryptionManager::~ClearKeyDecryptionManager()
{
CK_LOGD("ClearKeyDecryptionManager dtor");
}
void
ClearKeyDecryptionManager::Init(GMPDecryptorCallback* aCallback)
{
CK_LOGD("ClearKeyDecryptionManager::Init");
mCallback = aCallback;
mCallback->SetCapabilities(GMP_EME_CAP_DECRYPT_AUDIO |
GMP_EME_CAP_DECRYPT_VIDEO);
}
static string
GetNewSessionId()
{
static uint32_t sNextSessionId = 0;
string sessionId;
stringstream ss;
ss << ++sNextSessionId;
ss >> sessionId;
return sessionId;
}
void
ClearKeyDecryptionManager::CreateSession(uint32_t aPromiseId,
const char* aInitDataType,
uint32_t aInitDataTypeSize,
const uint8_t* aInitData,
uint32_t aInitDataSize,
GMPSessionType aSessionType)
{
CK_LOGD("ClearKeyDecryptionManager::CreateSession type:%s", aInitDataType);
// initDataType must be "cenc".
if (strcmp("cenc", aInitDataType)) {
mCallback->RejectPromise(aPromiseId, kGMPNotSupportedError,
nullptr /* message */, 0 /* messageLen */);
return;
}
string sessionId = GetNewSessionId();
assert(mSessions.find(sessionId) == mSessions.end());
ClearKeySession* session = new ClearKeySession(sessionId, mHost, mCallback);
session->Init(aPromiseId, aInitData, aInitDataSize);
mSessions[sessionId] = session;
const vector<KeyId>& sessionKeys = session->GetKeyIds();
vector<KeyId> neededKeys;
for (auto it = sessionKeys.begin(); it != sessionKeys.end(); it++) {
if (mDecryptors.find(*it) == mDecryptors.end()) {
// Need to request this key ID from the client.
neededKeys.push_back(*it);
mDecryptors[*it] = nullptr;
} else {
// We already have a key for this key ID. Mark as usable.
mCallback->KeyIdUsable(sessionId.c_str(), sessionId.length(),
&(*it)[0], it->size());
}
}
if (neededKeys.empty()) {
CK_LOGD("No keys needed from client.");
return;
}
// Send a request for needed key data.
string request;
ClearKeyUtils::MakeKeyRequest(neededKeys, request);
mCallback->SessionMessage(&sessionId[0], sessionId.length(),
(uint8_t*)&request[0], request.length(),
"" /* destination url */, 0);
}
void
ClearKeyDecryptionManager::LoadSession(uint32_t aPromiseId,
const char* aSessionId,
uint32_t aSessionIdLength)
{
// TODO implement "persistent" sessions.
mCallback->ResolveLoadSessionPromise(aPromiseId, false);
CK_LOGD("ClearKeyDecryptionManager::LoadSession");
}
void
ClearKeyDecryptionManager::UpdateSession(uint32_t aPromiseId,
const char* aSessionId,
uint32_t aSessionIdLength,
const uint8_t* aResponse,
uint32_t aResponseSize)
{
CK_LOGD("ClearKeyDecryptionManager::UpdateSession");
string sessionId(aSessionId, aSessionId + aSessionIdLength);
if (mSessions.find(sessionId) == mSessions.end() || !mSessions[sessionId]) {
CK_LOGW("ClearKey CDM couldn't resolve session ID in UpdateSession.");
mCallback->RejectPromise(aPromiseId, kGMPNotFoundError, nullptr, 0);
return;
}
// Parse the response for any (key ID, key) pairs.
vector<KeyIdPair> keyPairs;
if (!ClearKeyUtils::ParseJWK(aResponse, aResponseSize, keyPairs)) {
CK_LOGW("ClearKey CDM failed to parse JSON Web Key.");
mCallback->RejectPromise(aPromiseId, kGMPAbortError, nullptr, 0);
return;
}
mCallback->ResolvePromise(aPromiseId);
for (auto it = keyPairs.begin(); it != keyPairs.end(); it++) {
KeyId& keyId = it->mKeyId;
if (mDecryptors.find(keyId) != mDecryptors.end()) {
mDecryptors[keyId] = new ClearKeyDecryptor(mCallback, it->mKey);
mCallback->KeyIdUsable(aSessionId, aSessionIdLength,
&keyId[0], keyId.size());
}
mDecryptors[keyId]->AddRef();
}
}
void
ClearKeyDecryptionManager::CloseSession(uint32_t aPromiseId,
const char* aSessionId,
uint32_t aSessionIdLength)
{
CK_LOGD("ClearKeyDecryptionManager::CloseSession");
string sessionId(aSessionId, aSessionId + aSessionIdLength);
ClearKeySession* session = mSessions[sessionId];
assert(session);
const vector<KeyId>& keyIds = session->GetKeyIds();
for (auto it = keyIds.begin(); it != keyIds.end(); it++) {
assert(mDecryptors.find(*it) != mDecryptors.end());
if (!mDecryptors[*it]->Release()) {
mDecryptors.erase(*it);
mCallback->KeyIdNotUsable(aSessionId, aSessionIdLength,
&(*it)[0], it->size());
}
}
mSessions.erase(sessionId);
delete session;
mCallback->ResolvePromise(aPromiseId);
}
void
ClearKeyDecryptionManager::RemoveSession(uint32_t aPromiseId,
const char* aSessionId,
uint32_t aSessionIdLength)
{
// TODO implement "persistent" sessions.
CK_LOGD("ClearKeyDecryptionManager::RemoveSession");
mCallback->RejectPromise(aPromiseId, kGMPInvalidAccessError,
nullptr /* message */, 0 /* messageLen */);
}
void
ClearKeyDecryptionManager::SetServerCertificate(uint32_t aPromiseId,
const uint8_t* aServerCert,
uint32_t aServerCertSize)
{
// ClearKey CDM doesn't support this method by spec.
CK_LOGD("ClearKeyDecryptionManager::SetServerCertificate");
mCallback->RejectPromise(aPromiseId, kGMPNotSupportedError,
nullptr /* message */, 0 /* messageLen */);
}
void
ClearKeyDecryptionManager::Decrypt(GMPBuffer* aBuffer,
GMPEncryptedBufferMetadata* aMetadata)
{
CK_LOGD("ClearKeyDecryptionManager::Decrypt");
KeyId keyId(aMetadata->KeyId(), aMetadata->KeyId() + aMetadata->KeyIdSize());
if (mDecryptors.find(keyId) == mDecryptors.end() || !mDecryptors[keyId]) {
mCallback->Decrypted(aBuffer, GMPNoKeyErr);
}
mDecryptors[keyId]->QueueDecrypt(aBuffer, aMetadata);
}
void
ClearKeyDecryptionManager::DecryptingComplete()
{
CK_LOGD("ClearKeyDecryptionManager::DecryptingComplete");
for (auto it = mSessions.begin(); it != mSessions.end(); it++) {
delete it->second;
}
for (auto it = mDecryptors.begin(); it != mDecryptors.end(); it++) {
delete it->second;
}
delete this;
}
void
ClearKeyDecryptor::QueueDecrypt(GMPBuffer* aBuffer,
GMPEncryptedBufferMetadata* aMetadata)
{
CK_LOGD("ClearKeyDecryptor::QueueDecrypt");
mThread->Post(new DecryptTask(this, aBuffer, aMetadata));
}
void
ClearKeyDecryptor::Decrypt(GMPBuffer* aBuffer,
GMPEncryptedBufferMetadata* aMetadata)
{
if (!mThread) {
mCallback->Decrypted(aBuffer, GMPGenericErr);
}
// If the sample is split up into multiple encrypted subsamples, we need to
// stitch them into one continuous buffer for decryption.
vector<uint8_t> tmp(aBuffer->Size());
if (aMetadata->NumSubsamples()) {
// Take all encrypted parts of subsamples and stitch them into one
// continuous encrypted buffer.
unsigned char* data = aBuffer->Data();
unsigned char* iter = &tmp[0];
for (size_t i = 0; i < aMetadata->NumSubsamples(); i++) {
data += aMetadata->ClearBytes()[i];
uint32_t cipherBytes = aMetadata->CipherBytes()[i];
memcpy(iter, data, cipherBytes);
data += cipherBytes;
iter += cipherBytes;
}
tmp.resize((size_t)(iter - &tmp[0]));
} else {
memcpy(&tmp[0], aBuffer->Data(), aBuffer->Size());
}
assert(aMetadata->IVSize() == 8 || aMetadata->IVSize() == 16);
vector<uint8_t> iv(aMetadata->IV(), aMetadata->IV() + aMetadata->IVSize());
iv.insert(iv.end(), CLEARKEY_KEY_LEN - aMetadata->IVSize(), 0);
ClearKeyUtils::DecryptAES(mKey, tmp, iv);
if (aMetadata->NumSubsamples()) {
// Take the decrypted buffer, split up into subsamples, and insert those
// subsamples back into their original position in the original buffer.
unsigned char* data = aBuffer->Data();
unsigned char* iter = &tmp[0];
for (size_t i = 0; i < aMetadata->NumSubsamples(); i++) {
data += aMetadata->ClearBytes()[i];
uint32_t cipherBytes = aMetadata->CipherBytes()[i];
memcpy(data, iter, cipherBytes);
data += cipherBytes;
iter += cipherBytes;
}
} else {
memcpy(aBuffer->Data(), &tmp[0], aBuffer->Size());
}
mCallback->Decrypted(aBuffer, GMPNoErr);
}
ClearKeyDecryptor::ClearKeyDecryptor(GMPDecryptorCallback* aCallback,
const Key& aKey)
: mRefCnt(0)
, mCallback(aCallback)
, mKey(aKey)
{
if (GetPlatform()->createthread(&mThread) != GMPNoErr) {
CK_LOGD("failed to create thread in clearkey cdm");
mThread = nullptr;
return;
}
}
ClearKeyDecryptor::~ClearKeyDecryptor()
{
CK_LOGD("ClearKeyDecryptor dtor; key ID = %08x...", *(uint32_t*)&mKey[0]);
}
uint32_t
ClearKeyDecryptor::AddRef()
{
return ++mRefCnt;
}
uint32_t
ClearKeyDecryptor::Release()
{
uint32_t newCount = --mRefCnt;
if (!newCount) {
if (mThread) {
mThread->Post(new DestroyTask(this));
mThread->Join();
} else {
delete this;
}
}
return newCount;
}